Cal. Health & Saf. Code § 124085
On and after July 1, 1976, each child eligible for services under this article shall, within 90 days after entrance into the first grade, provide a certificate approved by the department to the school where the child is to enroll documenting that within the prior 18 months the child has received the appropriate health screening and evaluation services specified in Section 124040. A waiver signed by the child's parents or guardian indicating that they do not want or are unable to obtain the health screening and evaluation services for their children shall be accepted by the school in lieu of the certificate. If the waiver indicates that the parent or guardian was unable to obtain the services for the child, then the reasons why should be included in the waiver.
Ca. Health and Saf. Code § 124085